Catheter/guidewire combinations are used in conventional methods to access internal anatomical structures via the vasculature of a patient. Many peripheral and cardiac procedures are routinely performed, including angiography, angioplasty, and stent placement. In many procedures the ability to properly access the target anatomical structure is hampered or even prevented by tortuous or tight vessels. In fact, tortuous anatomy presents the single greatest challenge to the skilled clinician. Difficult turns and angled vessels often make for difficult passage. Inability to access the correct location may ultimately result in treatment failure, increased patient risk, and/or increased time in performing the medical procedure.
A number of companies have developed, or are developing, systems designed to magnetically manipulate and steer catheters (and other medical devices) inside the human body. In particular, a strong magnetic field is applied to the distal end of a catheter, which carries one or more magnetic elements (either permanent or electromagnetic magnets, or magnetic material, such as ferrous material), so that the resulting magnetic force moves the distal end of the catheter. The magnitude and direction of the magnetic force is determined by several factors: (a) the strength of the magnetic field; (b) the orientation (direction and polarity) of the magnetic field; and (c) the characteristics of the magnetic element(s) in the catheter. By controlling the strength and orientation of the magnetic field (e.g., using gimbaled sets of electromagnets), the catheter can be steered within the body, and/or made to apply contact force to the tissue within the body. While magnetic navigation systems have been generally successful in steering catheters through the vasculature of a patient, they are costly, as well as large and cumbersome.
Accordingly, there remains a need to provide a steerable catheter capable of being more efficiently guided through the vasculature of a patient.